Swinging bridge for saw-arbors



Unirrnn STATES,

PArENr @FFlC-E;

DONALD J. MURRAY, or wAUsAU, WISCONSIN.

SWINGING. BRIDGE FOR SAW-ARBORS.

SPECIFICATION forming part of Letters Patent No. 288,589, dated November13, 1883. Application filed July 7, 19.83. No model.)

To aZZ whom, it may concern.-

Be it known that I, DONALD J. MURRAY, a citizen of the United States,residing at Wausau, in the county of Marathon and' State of Wisconsin,have invented certain new and useful Improvements in SwingingBridge'Trees; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enableothers'skilled in the art to which it appertains to make and use thesame, reference being had to the ac companying drawings, and to lettersor figures of reference marked thereon, which form a part of thisspecification.

My invention is a swinging bridgetree for saw-arbors, and embraces thefollowing peculiar features: a bridge-tree hinged atone end and swingingout of the grooved and supporting cleats of the end of the saw-framewhich is opposite to that which supports the pulley end of thesaw-arbor; also, an arbor-box pivoted upon said bridge-tree, andprovided with a tapered bearing conforming to the journal of the arbor,and with two nut-bolts which secure and limit the turn of said box uponthe bridge-tree; and, lastly, two curving slots cut through thebridge-tree in conformitywith the slide of the heads of said nut-boltsin turning said arbor-box, all of which and their purposes arehereinafter more fully described, and illustrated by the accompanyingdrawings, in which the same letters designate identical parts of mydevice in the 'differentfigures, respectively.

Figure 1 illustrates an end view of a sawframe, showing my devicesecured in place. Fig. 2 illustrates a top view of the same. Fig.

3 illustrates the same top view, but showing my device swung out fromits supporting cleats, with the arbor-box turned, in withdrawing thesaid bearing from the tapered arborjournal, and in dotted linesthecurved slots cut through the bridge-tree. Fig. at illustrates a topview of the end of the frame support ing the pulley end of the arbor,showing the two sliding bridges on each side of the pulley.

The letterA represents the said bridge-tree, which is made of suitablemetal and dimensions, and substantially in the formshown in thedrawings. Its ends are firmly supported in the grooves of the cleats b,which either form a portion of the end of the saw-frame B or are firmlyand fittingly bolted. to the same, and

whenever the said bridge is swung outward, to 7 free the end of thearbor, to slip off or on the saws. The said conformable taper of the anbor-boX bearing e, as shown, together with said pivotal motion of thebox, greatly facili tates the ease and safety with which the wholedevice is slid off and upon the arbor F, the journal 9 of which alsotapers toward its outer. end, to assist the same result. In order toobviate the necessity or troubleof withdraw ing the nut-bolts z, andprevent the liability of displacing the cap of the arbor-box O, and yetallow said box to freely and automatically turn upon its pivot whilebeing withdrawn from the arbor by the said swing of the bridge, twocounter-curved slots, s, are cut through said bridge, as shown, in whichsaid bolts shall conformabl y slide with the said pivotal motion of thearbor-box. The said bridge-tree is also suitably curved at the swingingend, so that it may be easily slipped out and into its grooved cleat.

The pulley end of the arbor F is provided with two counter-supportingbridge-trees, H and K, which are slipped into and supported by theirrespective grooved cleats m and a, as shown, where they are secured bybolts or screws. These latter bridge-trees serve to support and, withthe pulley, suitably balance the arbor while the swinging bridge-tree A,with its arbor-box, is withdrawn, and the saws are being removed forfiling or other purpose, thereby saving the considerable time hithertolost and the necessitous trouble in removing the arbor altogether fromthe frame before the saws could be removed.

By means of my invention, constructed, fitted, and adjusted ashereinbefore described, the whole operation-namely, of slightlylooseningthe nut-bolts z, of swinging open the bridge-tree A, and thuswithdrawingthe automatically-turning arbor-box O, and entirely freeing the journalend g of the arbor F, and of removing the saws-is easily accomplished ina few minutesan operation which by the modes hitherto generally in usewould have taken at least an hour. Therefore What I claim as new, anddesire to secure by Letters Patent, is- I l. Inthe saw-frame B,thehinging and swinging bridge A, provided with the conformablycurvingslots 8, and carrying the automaticallyturning arbor-box 0, providedwith the adjustable pivot d, the, tapered bearing 0, and theadjustably-slidin g bolts 2', substantially as and for the purposesherein specified.

2. The hinging and swinging bridge-tree A,

having the automatically and adj ustably moving arbor-box O, incombination with the tapered journal 9 of the arbor F, and the slidingbridge-trees H and K, adjusted and secured in the grooved cleats m andn, respectively, of the frame B, and also supporting and balancing thepulley end of the arbor, substantially as and for the purposes hereinspecified.

In testimony whereof I affix my signature in 25 presence of twowitnesses.

' DONALD J. MURRAY.

\Vitnesses: GEO. W. THAYER,

V. A. ALDERSON.

